Mix together the butter, sugar and eggs until creamy.
Add the flour and baking powder.
Peel and chop up the apples into small chunks and add to the mixture along with the lemon juice.
Fill the mixture into your baking tin – I used a Large Silicon Loaf Tin as it’s easier to get the cake out as gluten-free cakes can be more crumbly.
Bake for 45-60 minutes at 180C

Leave to cool.

For the icing just mix the Icing sugar with the Lemon Juice and pour on top of the cake, then grate the rind of the lemon on top.